Breast-cancer checks save lives despite over diagnosis

October 29, 2012|Reuters

* Regular monitoring is best option, charity says

* Screenings are topic of international debate

* Critics say women undergo unnecessary treatments

By Chris Wickham

LONDON, Oct 30 (Reuters) - Breast-cancer screening saveslives even though it also picks up cases in some women thatwould never have caused them a problem, according to a reviewpublished in The Lancet medical journal.

The independent review, commissioned by the charity CancerResearch UK (CRUK) and Britain's Department of Health, followsfierce international debate about the benefits of routinescreening and recent research that has argued it does more harmthan good.

"This has become an area of high controversy," said Sir MikeRichards, the Department of Health's National Cancer Directorand one of the sponsors of the review.

Critics of routine screening argue that women can besubjected to unnecessary surgery, radiotherapy and medication totreat cancers that would have posed them no risk.

"Screening remains one of the best ways to spot the veryearly signs of breast cancer, at a stage when treatment is mostlikely to be successful," he said.

"Yet, as the review shows, some cancers will be diagnosedand treated that would never have caused any harm."

A panel of experts led by University College Londonprofessor Sir Michael Marmot concluded that screening preventsabout 1,300 deaths per year in Britain but can also lead toabout 4,000 women having treatment for a condition that wouldnever have troubled them.

This means that for every death that is prevented, threewomen are over-diagnosed.

The review panel called for improved information, in healthleaflets for instance, to give women a clearer picture of boththe benefits and potential harms before they go for a mammogram.

Breast cancer is the most common form of cancer among womenin Britain, affecting one in eight at some point in their lives.The country's screening programme invites women aged 50 to 70for a mammogram every three years and this is being expanded toages 47 and 73.

Earlier diagnosis and better treatments have improved thesurvival rate to 77 percent in 2007 from 41 percent in 1971,according to CRUK.

The conclusions of the review are based on analysis of 11trials that all took place more than 20 years ago, whichassessed whether screening resulted in fewer deaths due to thedisease, compared to when no screening takes place.

The panel acknowledged the studies had limitations, notleast because of their age, but decided the evidence was strongenough to conclude that women invited for screening have arelative risk of dying from breast cancer that is 20 percentless than those who are not invited.

Harpal Kumar said research is under way that could lead tomore sophisticated tests that distinguish aggressive cancersfrom those that are not.

This, coupled with a better understanding of geneticpredisposition and lifestyle factors that play a role in breastcancer, could mean more finely targeted screening and lessover-diagnosis.

"Until this is possible, we'd recommend women who have hadsomething unusual picked up through screening to seek fulladvice and discuss all possible options with their breast cancerspecialist team," he said.